Added Margin Loss Decoder

shogun-toolbox · May 20, 2012 · bf4e97f · bf4e97f
1 parent 788043e
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diff --git a/src/shogun/multiclass/ecoc/ECOCLLBDecoder.cpp b/src/shogun/multiclass/ecoc/ECOCLLBDecoder.cpp
@@ -0,0 +1,11 @@
+#include <shogun/multiclass/ecoc/ECOCLLBDecoder.h>
+
+using namespace shogun;
+
+float64_t CECOCLLBDecoder::compute_distance(SGVector<float64_t> outputs, const int32_t *code)
+{
+    float64_t loss = 0;
+    for (int32_t i=0; i < outputs.vlen; ++i)
+        loss += outputs[i]*code[i];
+    return -loss;
+}
diff --git a/src/shogun/multiclass/ecoc/ECOCLLBDecoder.h b/src/shogun/multiclass/ecoc/ECOCLLBDecoder.h
@@ -0,0 +1,46 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Written (W) 2012 Chiyuan Zhang
+ * Copyright (C) 2012 Chiyuan Zhang
+ */
+
+#ifndef ECOCLLBDECODER_H__
+#define ECOCLLBDECODER_H__
+
+#include <shogun/multiclass/ecoc/ECOCSimpleDecoder.h>
+
+namespace shogun
+{
+
+/** Margin Loss based decoder.
+ * Using OVREncoder with this Decoder should be equivlalent to
+ * traditional OVR Strategy.
+ */
+class CECOCLLBDecoder: public CECOCSimpleDecoder
+{
+public:
+    /** constructor */
+    CECOCLLBDecoder() {}
+
+    /** destructor */
+    virtual ~CECOCLLBDecoder() {}
+
+    /** get name */
+    virtual const char* get_name() const { return "ECOCLLBDecoder"; }
+
+protected:
+    /** whether to turn the output into binary before decoding */
+    virtual bool binary_decoding() { return false; }
+
+    /** compute distance */
+    virtual float64_t compute_distance(SGVector<float64_t> outputs, const int32_t *code)=0;
+};
+
+} /* shogun */ 
+
+#endif /* end of include guard: ECOCLLBDECODER_H__ */
+